Aerial camera



March 6, 1928. 1,661,364

l S. M. FAIRCHILD AERIAL CAMERA Filed March l, 1923 3 Sheets-Sheei l March 6, 1928. 1,661,364

s M. FAIRCHILD AERIAL CAMERA Filed Marchl 1, 1923 3 Sheets-Sheet 2 March 6, 1928. 1,661,364

v S. M. FAIRCHILD AERIAL CAMERA Filed March l, 1923 A 5 Sheets-Sheffv 3 Patented 6, 1928.

UITED STATES SHERMAN M. FAIRCHILD, 0F NEW YORK, Y.

.AERIAL CAMERA..

Application led March 1, 1923. Serial No. 622,034.

This invention relates to cameras, particularly cameras for aerial photography, 1n which the lens is carried by a tubular member, commonly known as the lens cone, extending from the front or, in aerial cameras usually from the bottom of the camera body. More especially the invention relates to the mounting of the cone on the camera, and its chie'object is to provide a method of mounting which will permita plurality of cones, for lenses of different focal lengths, to be used interchangeably. Cameras for aerial photography are commonly supported in universal mounts, so that as the airplane tilts in flight the camera can swing and thereby maintain its optical axis in a substantially constant position with reference to the ground or; other object or can, within certain limits imposed by the nature of the mounting, be trained on the object to be photographed. ln such cases the camera is supported pivotally, and 1t is usually de sirable to have the axis or axes, on which it swings, in or close to the center of gravity.

of the apparatus. Accordingly another object of this invention is to provide the lens cone or cones with pivotal means -by-which the axis ot swing is brought to the desired position with respect to the center ot gravity. Still another object is to provide a lens cone and lens mounting which will pers init various lenses ot nominally the saine or nearly the same focal length to he used interchangeahly without adjustment for locus To these y and.

when the change is made. other ends the invention consists in the novel "features hereinafter described.

A convenient and eilective embodiment ot the invention is illustrated in the `accompanyingdrawings, in which i Fig. l is a side view, partly in section, showing an aerial camera equipped with my lens cone, lens mount, and camera-supporte ing means.

Figs. 2 and 3 are side views, aty right angles 'to eachother, showing a eone (lor a lens oit shorter -local length) which is interchangeable with thatshown in Fig. l without substantial change in the position ot the axis ot the camerapivots with respect to the center of gravity.

Fig. l is side view oi a longer lens cone which is interchangeable with those of Figs. l and 2 in the same way.

Fig. 5 is a detail sectional view of the means for securing the lens in the cone.

Figs. 6 and 7 are side views illustrating a.

modified form of camera supporting means.

Fig. 8 isa detail view illustrating another modification.

rlhe camera body is represented at l0, and is equipped with a removable magazine l1 for the sensitive plates or film. rlhe nature of the magazine or other means for supporting the plate or film in is immaterial.

The lens l2 is mounted in a tubular carrier or cone 13, detachably mounted on the underside or' the camera. For this purpose the camera is provided with a suitable litting, vas a flange or collar il, around the opening l5, over which theupper end of the cone fits snugly so as to make a light-tight joint. The cone is releasably secured in place by bayonet studs 16 cooperating with bayonet slots 1'? so that it can 'be removed and replaced or another cone, of the saine4 `preferably one of the girnbal type, in which case the camera is itself provided with pivposition for exposure ots, or with bearings for pivots, on opposite sides. lt is also desirable 4in such cases to have the axis ot these pivots pass through or close tothe center el gravity of the carnera, and the practise heretofore has loe-en to mount the pivots on the camera body. lt will he seen, however, that il a lens ot dihlerent i'ocal length or different aperture be used," the position of the center oi' gravity will he altered, since the new lens will he nearer or `farther from the exposure plane, or of dii- L'erent weight, or both. This means that allanee oi? the camera will he disturbed unthe pivots are shifted. ln my present invention the diculty is overcome in a veryl gravity ot the apparatus when the lens is in place. ln Fig. Il one oi the pivots is shown at i8. lt is carried hy ankarrn i9 which is lined on the side ot the lens cone and extends upwardly so as to hring the pivot to the lll@ `bayonet studs.

plane of the center of gravity. The other pivot, not shown in Fig. 1, is similarly lo-4 cated on the opposite side of the cone, and both are spaced out from the camera body to Ipermit the slight rotation of the Cone required to "disengage the same from the A lens of shorter `focal length must be nearer to the plate or The center of gravity is thus raised, and accordingly higher pivot arms are usedmas shown for example in Figs. 2 `and 3, in which the pivots or journals`20, carried by the arms 21 on the cone 22, are seen to be relatively higher than the pivot 18 onthe cone 13, Fig. 1. The cones mentioned may be of the same or dierent lengths, according to the position of the lenses in the respective cones, as will be readily understood. Thus if the shorter focal length lens shown in dotted lines at 12a is mounted in the cone at the same dista-nce above the lower end as is the lens 12 in Fig. l, the cone 22 must, to permit its use on the same camera, be proportionately shorter. @n the other hand, a lens of greater focal length may so lower the center of gravity as to require t-he pivot arms to extend downwardly, as in Fig. 4, for example, in which the pivot or journal 23 is shown carried by a depending arm 2d mounted on the long cone v25 carrying the lens 12". l/Vhatever the taper and length of the cone, the upper end thereof should be shaped to tit the collar 14; with the desired snugness.

For some purposes it is not necessary to have the camera pivotally mounted, but it should, nevertheless, be so arranged that its center of gravity is in or near the plane in which lthe camera is supported. lin such cases 'a form of support such as illustrated in Figs. 6 and l may be used with advantage. .ls there shown each of the lens cones 22a and 25a is' provided with an outwardly flanged positioning ring 'l fixed thereon, removably seated in the camera support, which is l represented by the i'abbeted annulus 8 rigidly suspended by ar-ms 9 from any suitable-mounting means, not shown. -Or the parts 18, 20, 23, shown as pivots in Figs. 1, 2, 3 and 4C, can be angular studs, as 18a`in Fig.. 3, to lit into similarly shaped recesses in the camera support, not shown.

flhenses of different focalv length may be permanently mounted in their respective cones, and can then be used interchangeably on the same camera without the necessity of focusing when the lens and cone are changed.

IThis method is not always convenient, for it is sometimes desirable, and in fact sometimes necessary, as in case of breakagey of a lens, or derangement of the lens-shutter, for example, to substitute another lens of the same focal length, in the same cone. lil-lio'vever, lenses which have nominally the same focus are often dihferent in that respect, by an amount sufficient to affect the definition on inattesa correct position for the lens. This support in the form shown has at its bottomn an inwardly extending flange 28 to support t-he shutter 2G, and at its top an outwardly extending flange 29 to receive the screws 30 by which the whole is removably secured in the cone. The shutter or carrier 26 is provided with a plurality of downwardly internally threaded open apertures or sockets, as 31, containing threaded adjusting plugs or stops 32 the lower ends of which rest on the Harige 28. l/Vhen the lenses usable with the given cone and support are assembled in their shutters, each is set down in place and the stops 32 are screwed in or out, as the case may be,

until'the image of a distant object, for example an object at the hyperfocal distance, is sharp on the focussing screen. This adjustment canv be conveniently effected by means of a suitable wrench or other tool, not shown, inserted through the exposure opening providedy in the flange 28. The lens and shutter assembly is the-n removed and holes are drilled through the sides of the shutter and into the adjusting stops, to receive the tightly tt-ing pins 34, whichv serve to prevent accidental displacement of the stops and consequent 'impairment of the adjustment. Any lens thus focussed can now be removed and replaced as often as desired with the assurance that when the screws 33 are set up it will be in accurate focus for all ob jects within lthe range for which it was originally focussed. The shutter illustrated is set and tripped from the camera body 10 by means of shafts 35, detachably connected to the universal joints 36, As the lens cone is positioned on the camera the shafts are guided into engagement with the appropriate universal lioints by the operators hand inserted into the cone from above, the plate or film carrier or magazine 11 beingl of course embodied in other forms without departure fromits spirit. Nor are all the features of the invention limited to use in aerial photography.

ll claim l. lin aphotographie apparatus, a camera,

a detachable lens cone therefor, and means l mense@ carried by the lens cone for pivotally supporting the camera t0 permit swinging movement of the latter on an axis having a predetermined position relative to the center of gravity of the apparatus.

2. ln a photographic apparatus, a camera, a detachable lens cone provided with means for releasably locking it on the camera, and having means for pivotally supporting the camera to swing on an axis located in a predetermined position relative to the center of gravity of the apparatus.

3. ln a photographic apparatus, a camera., a detachable lens cone therefor, and a pair of pivot-arms, mounted on opposite sides of the lens cone and having transversely aligned pivotal supporting means to permit swinging movement of the camera on an axis located within a predetermined distance from the center of gravity of the apparatus.,

Il. In aerial photographic apparatus, a camera having a lens pone, and a-plurality of interchangeably usable lenses each havingpre-adjusted means for causing the lens to assume automatically the position of focus when seated in the cone.

5. lin aerial photographic apparatus, a camera having a lens cone provided with a lens-support, and a plurality of interchangeably usable lenses each provided with preadfjusted means to cooperate With the support and cause the lens to assume automatically the position of focus when seated on said support.

6. ln a photographie apparatus, a camera, and means for equipping the camera with any one of a plurality of lens cones adapted to be interchangeably mounted on the camera in a common fixed position with respect to the exposure plane, a plurality of lenses each mounted in predetermined fixed position in its respective cone, and the several cones having means for pivotally supporting the camera to permit the same to swing on axes in substantially the same predetermined position with respect to the center of gravity of the apparatus.

7. In aerial photographic apparatus, a camera, a lens cone removably and non-adjustably mounted thereon, and a lens removably and non-adjustably secured in the lens cone in position of focus.

8. A lens cone adapted to be removably and non-adjustably mounted on an aerial camera, and a lens fixedly mounted in the cone in pre-adjusted position of focus.

9. A lens cone adapted to be removably and non-adjustably mounted on an aerial camera, a lens support in fixed position in the cone, and a lens fixed in pre-adjusted position of focus in the support.

In testimony whereof I hereto affix my signature.

SHERMAN M. FAIRCHILD. 

